I mount my knife sideways along my PFD's waist strap. The knife sheath has two screw mounts...I used a heated drill bit to melt two holes in the waist strap (nylon web) at the appropriate location. This way the knife is out of the way and resists catching on things. IWhen racing I'm usually wearing a lycra stretch top over everything, and it keeps the knifie accessible yet snag proof.